/*
 * kankan
 * 2016/2/21 1:11
 * 根据文件名异步上传文件，支持多文件
 */
jQuery.extend({
	createUploadIframe : function(id, uri) {
		//create frame
		var frameId = 'jUploadFrame' + id;
	
		if (window.ActiveXObject) {
			var io = document.createElement('<iframe id="' + frameId
					+ '" name="' + frameId + '" />');
			if (typeof uri == 'boolean') {
				io.src = 'javascript:false';
			} else if (typeof uri == 'string') {
				io.src = uri;
			}
		} else {
			var io = document.createElement('iframe');
			io.id = frameId;
			io.name = frameId;
		}
		io.style.position = 'absolute';
		io.style.top = '-1000px';
		io.style.left = '-1000px';
	
		document.body.appendChild(io);
	
		return io;
	},
	
	createUploadForm : function(id, fileNameAttrValues) {
		//create form 
		var formId = 'jUploadForm' + id;
		var fileId = 'jUploadFile' + id;
		var form = jQuery('<form  action="" method="POST" name="'
				+ formId + '" id="' + formId
				+ '" enctype="multipart/form-data"></form>');

		if (typeof (fileNameAttrValues) == 'string') {
			fileNameAttrValues = [ fileNameAttrValues ];
		}
		for (var i in fileNameAttrValues){
			var oldElement = jQuery("input[name=" + fileNameAttrValues[i] + "]");
			var newElement = jQuery(oldElement).clone();    
			jQuery(oldElement).attr('id', fileId);    
			jQuery(oldElement).before(newElement);    
			jQuery(oldElement).appendTo(form);
		}
		
		//set attributes
		jQuery(form).css('position', 'absolute');
		jQuery(form).css('top', '-1200px');
		jQuery(form).css('left', '-1200px');
		jQuery(form).appendTo('body');
		return form;
	},

	ajaxFileUpload : function(s) {
		// TODO introduce global settings, allowing the client to modify them for all requests, not only timeout  
		s = jQuery.extend({}, jQuery.ajaxSettings, s);
		var id = s.fileNameAttrValues;
		var form = jQuery.createUploadForm(id, s.fileNameAttrValues);
		var io = jQuery.createUploadIframe(id, s.secureuri);
		var frameId = 'jUploadFrame' + id;
		var formId = 'jUploadForm' + id;
	
		if (s.global && !jQuery.active++) {
			// Watch for a new set of requests
			jQuery.event.trigger("ajaxStart");
		}
		var requestDone = false;
		// Create the request object
		var xml = {};
		if (s.global) {
			jQuery.event.trigger("ajaxSend", [ xml, s ]);
		}
	
		var uploadCallback = function(isTimeout) {
			// Wait for a response to come back 
			var io = document.getElementById(frameId);
			try {
				if (io.contentWindow) {
					xml.responseText = io.contentWindow.document.body ? io.contentWindow.document.body.innerHTML
							: null;
					xml.responseXML = io.contentWindow.document.XMLDocument ? io.contentWindow.document.XMLDocument
							: io.contentWindow.document;
	
				} else if (io.contentDocument) {
					xml.responseText = io.contentDocument.document.body ? io.contentDocument.document.body.innerHTML
							: null;
					xml.responseXML = io.contentDocument.document.XMLDocument ? io.contentDocument.document.XMLDocument
							: io.contentDocument.document;
				}
			} catch (e) {
				jQuery.handleError(s, xml, null, e);
			}
			if (xml || isTimeout == "timeout") {
				requestDone = true;
				var status;
				try {
					status = isTimeout != "timeout" ? "success"
							: "error";
					// Make sure that the request was successful or notmodified
					if (status != "error") {
						// process the data (runs the xml through httpData regardless of callback)
						var data = jQuery.uploadHttpData(xml, s.dataType);
						if (s.success) {
							// ifa local callback was specified, fire it and pass it the data
							s.success(data, status);
						}
						;
						if (s.global) {
							// Fire the global callback
							jQuery.event.trigger("ajaxSuccess", [ xml,
									s ]);
						}
						;
					} else {
						jQuery.handleError(s, xml, status);
					}
	
				} catch (e) {
					status = "error";
					jQuery.handleError(s, xml, status, e);
				}
				;
				if (s.global) {
					// The request was completed
					jQuery.event.trigger("ajaxComplete", [ xml, s ]);
				}
				;
	
				// Handle the global AJAX counter
				if (s.global && !--jQuery.active) {
					jQuery.event.trigger("ajaxStop");
				}
				;
				if (s.complete) {
					s.complete(xml, status);
				}
				;
	
				jQuery(io).unbind();
	
				setTimeout(function() {
					try {
						jQuery(io).remove();
						jQuery(form).remove();
	
					} catch (e) {
						jQuery.handleError(s, xml, null, e);
					}
	
				}, 100);
	
				xml = null;
	
			}
			;
		}
		// Timeout checker
		if (s.timeout > 0) {
			setTimeout(function() {
	
				if (!requestDone) {
					// Check to see ifthe request is still happening
					uploadCallback("timeout");
				}
	
			}, s.timeout);
		}
		try {
			var form = jQuery('#' + formId);
			jQuery(form).attr('action', s.url);
			jQuery(form).attr('method', 'POST');
			jQuery(form).attr('target', frameId);
			if (form.encoding) {
				form.encoding = 'multipart/form-data';
			} else {
				form.enctype = 'multipart/form-data';
			}
			jQuery(form).submit();
	
		} catch (e) {
			jQuery.handleError(s, xml, null, e);
		}
		if (window.attachEvent) {
			document.getElementById(frameId).attachEvent('onload',
					uploadCallback);
		} else {
			document.getElementById(frameId).addEventListener('load',
					uploadCallback, false);
		}
		return {
			abort : function() {
			}
		};
	
	},

	uploadHttpData : function(r, type) {
		var data = !type;
		data = type == "xml" || data ? r.responseXML : r.responseText;
		// ifthe type is "script", eval it in global context
		if (type == "script") {
			jQuery.globalEval(data);
		}
	
		// Get the JavaScript object, ifJSON is used.
		if (type == "json") {
			/* :k+ */
			data = r.responseText;
			var start = data.indexOf(">");
			if (start != -1) {
				var end = data.indexOf("<", start + 1);
				if (end != -1) {
					data = data.substring(start + 1, end);
				}
			}
			eval("data = " + data);
		}
	
		// evaluate scripts within html
		if (type == "html") {
			jQuery("<div>").html(data).evalScripts();
		}

		return data;
	}
});